It is well known that soft drinks are typically made by combining a syrup with carbonated water or soda. In the soft drink industry, it is known that the flow rate of syrup is a function of its viscosity and that the viscosity is a function of temperature. As the temperature drops, sugar-based syrups become thicker and, for a given pressure head, flow slower through the system. In like manner, as the temperature rises, such syrups become thinner and, for a given pressure head, flow more rapidly throughout the system. Accordingly, temperature or viscosity compensation must be considered for soft drink dispensing systems to assure a consistency in the brix level of the soft drinks dispensed, irrespective of temperature or syrup viscosity.
Previously, it has been proposed to rechamber the syrup from a bulk supply, monitor temperature of the rechambered syrup, and adjust the dispensing pressure head and/or dispensing cycle times to assure a proper amount of syrup is dispensed. While such systems are extremely accurate and reliable in operation, they are expensive to manufacture. Such systems typically require sophisticated electronic control circuitry, including the requisite software and firmware for control of the microprocessor systems which are often employed.
Previously, there has been no known way to dispense syrup from a bulk reservoir such as a pressurized canister or the now-popular "bag-in-a-box," or to assure a constant syrup flow rate or dispensing volume irrespective of syrup temperature or viscosity.